Date: Fri, 08 Apr 2022 16:58:43 +0000 From: bugzilla-noreply@freebsd.org To: net@FreeBSD.org Subject: [Bug 252165] usb network and mii bus media status race condition Message-ID: <bug-252165-7501-3sS65Zs3In@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-252165-7501@https.bugs.freebsd.org/bugzilla/> References: <bug-252165-7501@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D252165 --- Comment #19 from Ali Abdallah <ali.abdallah@suse.com> --- (In reply to Hans Petter Selasky from comment #18) Compiling the kernel with COPTFLAGS=3D-O0 and CFLAGS=3D-O0 resulted in non-= working dtrace... (dtrace: invalid probe specifier... "/usr/lib/dtrace/mbuf.d", lin= e 1: failed to copy type of 'm_data': Type information is in parent and unavailable.) But anyway the problem occurs, with no particular dmesg from witness or debug_lock. On the other hand, on the standard generic kernel, when the issue is not occurring, the following dtrace is shown # dtrace -n "fbt:kernel:mii_pollstat:*,fbt:uether:ue_tick_task:*,fbt:if_ure:ure_tick:*,= fbt:if_ure:ure_ifmedia_sts:*,fbt:kernel:mii_tick:*" 0 92491 ure_ifmedia_sts:entry=20 0 35254 mii_pollstat:entry=20 2 35255 mii_pollstat:return=20 2 92492 ure_ifmedia_sts:return=20 3 92425 ue_tick_task:entry=20 3 92489 ure_tick:entry=20 3 35276 mii_tick:entry=20 3 35277 mii_tick:return=20 3 92490 ure_tick:return=20 Which are the two "code-path" checking for link status. Now with the same dtrace probes, when the link up/down problem occurs, I see=20 3 92425 ue_tick_task:entry=20 3 92489 ure_tick:entry=20 3 35276 mii_tick:entry=20 0 92491 ure_ifmedia_sts:entry <---- 0 35254 mii_pollstat:entry <---- 3 35277 mii_tick:return=20 3 92490 ure_tick:return How that is possible? ure_ifmedia_sts should acquire the same mutex lock as ue_tick_task before calling mii_pollstat. And this is not happening apparen= tly. --=20 You are receiving this mail because: You are the assignee for the bug.=
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